The German Aerospace Center (DLR) has participated by means of computer simulations in the design and development of a new type of mechanism that enables the targeted release of unmanned aerial vehicles (UAVs) from the tail ramp of a flying transport aircraft. The project was carried out in cooperation with Airbus, Geradts GmbH and SFL GmbH.
Based on an agile design and development approach, the development and completion of a prototype, for which flight test certification was applied for, took place in only six months, starting with the generation of ideas via computer simulation.
The resulting system allows unmanned aerial vehicles to be deployed in areas they cannot reach independently. In flight, the UAVs are lowered from the rear of the transport aircraft by means of the developed mechanism in order, for example, to carry out targeted reconnaissance work from the air.
The main task of the DLR researchers was to use numerical simulations to determine conditions that would ensure safe separation of the UAV from the transport aircraft. The generation of large lift forces on the aerodynamically shaped UAV must be ruled out in order to prevent a collision between the transport aircraft and the UAV. This challenge exists especially behind the transport aircraft where air turbulence occurs. At the same time, the UAV should be able to assume a stable flight state immediately after setting down.
For this purpose, the influence of different variables, such as the position of the transport aircraft or the speed and attitude of the UAV relative to the transport aircraft, was investigated in elaborate numerical simulations. Since not only the aerodynamic forces, but also the response of the UAV to these forces are crucial for a safe descent, multidisciplinary simulations were carried out in which the flow solver was coupled with a flight mechanics tool. Proven DLR simulation methods for fluid dynamics and flight mechanics were used.
All partners collaborated in the project across divisions. The management of the project as well as the provision of a full-size A400M loading ramp for the implementation of the airdrop mechanism was carried out by Airbus, the company Geradts GmbH was responsible for the detailed design as well as the construction of the prototype of the mechanism and the company SFL GmbH was responsible for the project-specific modification of the UAV.
The project is part of the "Innovations for FCAS" (I4 FCAS) initiative, which aims to involve German non-traditional defense players, covering startups, small and medium-sized enterprises (SMEs) and research institutes, in the development of the Future Combat Air System (FCAS). This initiative, launched in April 2020, was funded by the German Ministry of Defense.